In order to improve the structural safety and stability of the tunnels crossing stick‐slip fault, an indoor model test on the effect of tunnel antibreaking measures under the influence of fault stick‐slip movements was conducted. Using contact pressure, longitudinal strain, and safety factor, the antibreaking effect of tunnels was compared and analyzed under 5 kinds of operating conditions, mainly including no measures, structural strengthening, structural strengthening and reducing dislocation layer, structural strengthening and reducing dislocation joint, structural strengthening and reducing dislocation layer, and reducing dislocation joint. The results showed that the longitudinal strain and contact pressure of the tunnel changed markedly (from severe change to more uniform change) when the reducing dislocation measures were adopted in the test, reducing dislocation layer/joint or reducing dislocation layer and reducing dislocation joint. The effect of reducing the fault stick‐slip dislocation on the tunnel structure is very limited by only taking structure strengthening measures. The effect of reducing the fault stick‐slip dislocation on the tunnel structure is obvious by using the reducing dislocation method, and the minimum safety factor is increased by more than 8 times. The effect of resisting and reducing the fault stick‐slip dislocation on the tunnel structure is remarkable by adopting the measures of the structural strengthening and reducing dislocation layer and reducing dislocation joint, and the minimum safety factor is increased by more than 25.45 times. The results can provide reference for the design of antibreaking for the stick‐slip fault tunnel in high earthquake intensity and dangerous mountainous areas.

In order to solve the problem of freezing damage treatment and anti-freezing design for railway tunnels in operation in the seasonal frozen area, this paper proposes a polyurethane-corrugated steel plate insulation lining, and studies its thermal insulation effect, relying on a freezing damage treatment project of an existing passenger-dedicated tunnel for on-site application. In this paper, the insulation lining is applied to the actual project and the insulation effect is verified by the field monitoring. The temperature test section was set in the anti-freezing design section. The polyurethane-corrugated steel plate insulation lining proposed in this paper is mainly composed of corrugated steel plate, polyurethane insulation layer and waterproof layer. The polyurethane-corrugated steel insulation lining is applied by using self-made rail flat battery car, door-type scaffolding, arch slide and other construction equipments. The on-site temperature test shows that the insulation effect is obvious. The polyurethane-corrugated steel plate insulation lining has the advantages of fast construction speed, good thermal insulation effect, preventing concrete from peeling off blocks, easy removal and replacement. According to the field temperature test, under the natural temperature outside the tunnel from −18°C to −22°C in winter of 2018–2020, the temperature of the interface between surrounding rock and lining of the tunnel monitoring sections are all above 0°C so that the freezing damage is eliminated from the root. Research results can provide a theoretical basis for the anti-freezing projects of tunnels in seasonal frozen area.

Based on the background of the Line F_2-3 interval tunnel section of Jiujiawan in Urumqi Subway Line 1, this paper carries out the model test research on the antibreaking technology of the reducing dislocation layer in the tunnel section of the stick‐slip fracture. The antibreaking effect of different locations and number of reducing dislocation layers in tunnel engineering is analyzed in this paper. The results show that when the double reducing dislocation layer, respectively, set between the surrounding rock and the primary support, and the primary support and the secondary lining, the antibreaking effect is the best. It is recommended to use this scheme for antibreaking design. The research results can provide reference for antibreaking design of traffic tunnels in active fault zones.

In order to study the antibreaking effect of the fiber reinforced concrete lining in the tunnel, this paper takes the a subway tunnel engineering project in F_2-3 section of Jiujiawan fault as the research background and carries out the antibreaking model test of the fiber reinforced concrete lining in the active fault zone of high earthquake intensity. The results show that the antibreaking effect of the principle stress and the longitudinal strain of the fiber reinforced concrete lining are 3040 and 8090, respectively, and the minimum value of the structural safety factor is increased by 45 times. The antibreaking effect of hybrid fiber reinforced concrete lining is better than that of steel fiber reinforced concrete lining. The safety of steel polypropylene hybrid fiber reinforced concrete tunnel lining is the highest, and its minimum structural safety factor is 1.62. In the aspect of improving the antibreaking effect of the tunnel, the toughening effect of fiber reinforced concrete is stronger than that of reinforcing. The research results are of great significance to improve the antibreaking effect of tunnels in active fault areas with high earthquake intensity.